Moroccan desert rivers: fish on the arid extreme of Mediterranean streams | FiSHMED journal (original) (raw)

ISSN 2386-8228

DOI 10.29094/FiSHMED

Miguel Clavero, Abdeljebbar Qninba, María Riesco, Javier Esquivias, Javier Calzada and Miguel Delibes

FiSHMED 2017.003: 21p

Abstract : Northern Africa presents a continuous aridity gradient related to geographic position and elevation that marks a change in river dynamics, from typical Mediterranean regimes to ephemeral desert water courses, in which prolonged dry periods without superficial flow alternate with violent flash floods. The region is also a spatially and temporally dynamic border area, occupied by a biota of mixed Palearctic and Afrotropical affinities. Here we describe the fish fauna of the main desert river basins in Morocco, highlighting its conservation status and suggesting possible research lines to be developed in the area. We focus in the basins of Oueds (= rivers) Draa, Ziz and Ghir, which drain the southern slopes of the High Atlas mountain chain, and use both our own field data from extensive surveys and already published information.

The studied basins contain nine native species, including cold-water species (two trout species), taxa with Mediterranean affinities (Luciobarbus, Aphanius) and three Afrotropical relict cichlids. Two species, the Dades trout (Salmo multipunctata) and the Sahara aphanius (Aphanius saourensis) are in critical need of conservation efforts. Eleven non-native species have been recorded in the area, of which eight are apparently established. Non-native species are closely linked to reservoirs from where they seem to have excluded native species. Flow regulation facilitates the colonization of downstream reaches by non-natives, while unregulated river reaches are dominated by native species. Authorities should work towards avoiding new introductions and the spread of already established non-native species.

Preserving, and ideally recovering the bio-geographic mosaic of Northern African river basins should be an international conservation target.

Keywords : Desert rivers, Sahara Desert, Atlas Mountains, Fish conservation, Invasive species, Reservoirs

Citation : Clavero M, Qninba A, Riesco M, Esquivias J, Calzada J, Delibes M (2017) Fish in Moroccan deser rivers: the arid extreme of Mediterraenean streams. Fishes in Mediterranean Environments 2017.003: 21p. https://doi.org/10.29094/FiSHMED.2017.003

Article first published online : 11 Oct 2017

FiSHMED is an international scientific journal edited by
the Iberian Society of Ichthyology – SIBIC